Mr. Beheshti, 35, wrote about politics and human rights in his blog, Magalh 91, according to the UN agency. He was arrested last month, and died while in detention on 6 November – his body was retrieved by his family for burial, and is said to have shown signs of violence.

“It is essential to respect the right of citizen and professional journalists to speak and write without fearing for their lives,” Ms. Bokova added. “Freedom of expression is a basic human right and essential component of democracy, good governance and rule of law.”